The main limitation of the census data is that it is only available for a single point in time in 2013. Although data from the 2018 census will eventually become available, we also need a way to track the number of women on an ongoing basis. We can do this using tax records from the IRD.
Methodology
Tax records are used to identify people who received income from a business in an industry relating to one of the trades. Information about occupation is not available in IRD records so we use only industry to identify people. We use the same core industries for the census data.
The workforce in a sector consists of those who earned income from businesses in industries relevant to each trade sector. An individual is included as an employee in a particular quarter if they received at least $1500 in wages or salary for that quarter. An employer is included in a particular tax year if they received any income from a business that year. Employer data is not available on a quarterly basis. Yearly numbers are calculated as averages of the quarters.
